1. Field of the Invention
The subject invention relates to methods and apparatus for improving contrast and resolution of a predetermined response of an object to illumination, to methods and apparatus having such improved contrast and resolution, and, more specifically, to microscopy and similar techniques in which an object is scanned by an array of light spots.
2. Information Disclosure Statement
The following disclosure statement is made pursuant to the duty of disclosure imposed by law and formulated in 37 CFR 1.56(a). No representation is hereby made that information thus disclosed in fact constitutes prior art, inasmuch as 37 CFR 1.56(a) relies on a materiality concept which depends on uncertain and inevitably subjective elements of substantial likelihood and reasonableness and inasmuch as a growing attitude appears to require citation of material which might lead to a discovery of pertinent material though not necessarily being of itself pertinent. Also, the following comments contain conclusions and observations which have only been drawn or become apparent after conception of the subject invention or which contrast the subject invention or its merits against the background of developments which may be subsequent in time or priority.
Also, no preamble of any statement of invention or claim hereof is intended to represent that the content of that preamble is prior art, particularly where one or more recitations in a preamble serve the purpose or providing antecedents for the remainder of a statement of invention or claim.
In a Letter to the Editors, in the Feb. 10, 1951 issue of NATURE, page 231, J. Z. Young and F. Roberts proposed a flying-spot microscope, suggesting that resolution should be substantially greater with the flying-spot than with a conventional microscope, since only one resolvable region is illuminated at a time. Young and Roberts also considered the possibility of quantitative analysis as perhaps the most important of all advantages of a flying-spot microscope.
Some seventeen years later, M. Petran, M. Hadravsky, M. D. Egger and R. Galambos, published their article entitled Tandem-Scanning Reflected-Light Microscope, in the Journal of the Optical Society of America, vol. 58, May 1968, pp. 661 to 664. That article disclosed a principle which was patented in several countries, including the United States, which issued U.S. Pat. No. 3,517,980 to M. Petran and M. Hadravsky on Jun. 30, 1970, for Method and Arrangement for Improving the Resolving Power and Contrast.
The heart of the tandem-scanning reflected-light microscope by Drs. Petran and Hadravsky is a rotating scanning disk in the form of a Nipkow wheel having a multitude of holes arranged in an Archimedean spiral. Predetermined ones of those holes were illuminated for the formation of a continuous stream of light spots scanning the object when the Nipkow wheel was rotated, while conjugate holes on that rotating disk or scanning wheel pass the reflected portion of light to an eye piece or similar device for observation.
There followed theoretical treatments of scanning microscopy, as may be seen from W. T. Welford, On the relationship between the modes of image formation in scanning microscopy and conventional microscopy, Journal of Microscopy, Vol. 96, August 1972, pp. 105-107, C. J. R. Sheppard and A. Choudhury, Image formation in the scanning microscope, OPTICA ACTA, 1977, Vol. 24, pp. 1051-1073, C. J. R. Sheppard and T. Wilson, Image formation in scanning microscopes with partially coherent source and detector, OPTICA ACTA, 1978, Vol. 25, pp. 315-325, G. J. Brakenhoff, P. Blom and P. Barends, Confocal scanning light microscopy with high aperture immersion lenses, Journal of Microscopy, Vol. 117, November 1979, pp. 219-232, and G. J. Brakenhoff, Imaging modes in confocal scanning light microscopy (CSLM), Journal of Microscopy, Vol. 117, November 1979, pp. 233-242.
The Tandem Scanning Reflected Light Microscope (TSRLM) appeared again in the literature in the form of two articles by M. Petran, M. Hadravsky, J. Benes, R. Kucera and A. Boyde, comprising Part 1--the principle, and its design, and Part 2--Pre--Micro '84 Applications at UCL, Proceedings RMS, Vol. 20, May 1985, pp. 125-139, dealing primarily with application of the TSRLM to dental research and related activities.
For further background on intravital microscopy, reference may be had to my article entitled Intravital Microscopy on the Basis of Telescopic Principles: Design and Application of an Intravital Microscope for Microvascular and Neurophysiological Studies, published in MODERN TECHNOLOGY IN PHYSIOLOGICAL SCIENCES, Academic Press, London, 1973, pp. 125-153, my article Laser Stimulation of Fluorochromes in Intravital Microscopy Using a Mirror Objective, published in METHODOLOGY IN MICROCIRCULATION, pp. 19-24, 7th European Conference on Microcirculation, Aberdeen, 1972, and my article entitled Intravital Microscopy, published in ADVANCES IN OPTICAL AND ELECTRON MICROSCOPY, Academic Press, vol. 6, 1979, pp. 1-47.
In addition to the utility mentioned in the further course of this disclosure, the methods and apparatus of the subject invention and of its embodiments herein disclosed also have utility in intravital microscopy, to name a further example.